It is generally the case, when using a conveyor belt to convey any of a variety of medicinal pills or other such small separate objects or any of a variety of separate sheets of sheet-like papers at high speed, that the paper or small object, being lightweight, is while being conveyed apt to float above the conveyor belt due to air resistance, which can prevent it from being conveyed in its proper orientation.
The present invention relates to a conveyor belt that conveys a lightweight sheet-like object or lightweight pill or granule-like object and/or lightweight clumpy object, the object being of such size as to allow it to be placed within the width of the belt, and relates to a conveyor apparatus employing such conveyor belt.
The present invention therefore relates to a conveyor belt having a structure such as will, when using a conveyor belt to convey paper for a copy machine, i.e., electrophotographic apparatus, or medicinal pills or other such small objects which are lightweight individual objects at high speed, prevent such papers or medicinal pills or other such small objects which are lightweight individual objects from floating above the conveyor belt while being conveyed and allow them to be conveyed in their proper orientations, and in particular to a conveyor belt comprising woven fabric in which the belt material is formed from fibers, and relates to a conveyor apparatus employing such a conveyor belt.
Conveyor belts—also called transport belts—which convey objects have typically been used most regularly at factories and the like where mass production is taking place. Such belts are made of rubber, woven fabric, wire mesh, steel plate, or other material. Such belts are suspended in loop-like fashion between belt pulleys provided at either end thereof, an object which is to be conveyed being conveyed when placed on such a belt due to motion of the belt. And such conveyor belts for conveying objects to be conveyed are used not only at the aforesaid factories and the like where mass production is taking place, but are incorporated in treatment apparatuses and/or processing apparatuses that treat and/or process individual objects, being employed within such apparatuses to convey objects to be treated and/or objects to be processed. Examples of such processing apparatuses include, for example, conveyor belts that convey medicinal pills, conveyor belts that convey copier paper for electrophotographic apparatuses within the apparatus, and so forth.
Some conveyor belts employ base material comprising fabric which has been woven into a mesh structure that has been made into a belt for conveying any of a variety of objects. Examples of such conveyor belts comprising fabric woven into a mesh structure will be described in turn below.
First, proposed as a belt having a mesh structure is a conveyor belt formed by causing a sturdy fabric which is a separate piece of cloth and which has a structure that is other than mesh structure to be stitched thereto in overcast fashion along a fixed width at the ends on either side of the belt.
Second, a conveyor belt is proposed which comprises a mesh belt woven from yarn comprising synthetic fibers and which is formed by causing reinforcing synthetic fiber fabric to cover and fuse with the ends on either side of this mesh belt.
Third, a conveyor belt has been developed which has a belt core that is woven in mesh-like fashion from glass fibers, the belt being such that a plurality of seal strips formed from resin or flexible material are integrally provided in row-like fashion in the conveying direction, being formed so as to protrude from the inner and outer surfaces thereof, and the belt side ends are moreover reinforced with fabric or other such reinforcing material in such fashion as to straddle the belt core.
Fourth is a filter mesh belt formed from a mesh portion formed between portions formed at either side in the long direction and a plurality of reinforcing portions arranged so as to cross the mesh portion, these side portions and these reinforcing portions being woven more tightly than the mesh portion and being imparted with more rigidity than the mesh portion. Hot-melt fibers are moreover woven into the side portions and reinforcing portions, application of heat treatment thereto causing these to be molded together in integral fashion, this integrally molded belt being what is proposed.
Fifth, a conveyor belt for a dryer has been proposed which is an air-permeable belt for carrying out cooling and/or drying at normal pressure of raw materials while blowing hot or cold air thereonto, this conveyor belt being used in an apparatus in which a blower box formed by arranging a perforated plate at the top surface is brought into intimate contact with the bottom surface of a conveyor belt comprising a mesh belt, hot or cold air being blown from the blower box so as to dry or cool the raw materials atop the mesh belt.
Sixth, proposed is a belt comprising a 1-mm to 2-mm warp parallel to the mesh belt conveying direction and comprising a 0.1-mm to 0.5-mm weft perpendicular to this warp, the mesh belt which has a mesh opening ratio of 15% to 40% being coated or impregnated with silicone rubber for formation thereof.
Seventh, proposed is a belt which comprises a solid belt, holes for air permeability being formed in this solid belt, irregular groove shapes parallel to the belt conveying direction being present, height of the irregular groove shapes being not less than 0.1 mm, the irregular shapes repeating with a periodicity that is not less than 1 mm, height of unevenness in paper which is the object to be conveyed being reduced by suction means.
Eighth, proposed is a belt which is a mesh belt wherein a guide rib member is arranged on a back surface at an edge of the belt, engagement of this guide rib member with a guide groove formed therebelow preventing lateral displacement in the axial direction.
Ninth, proposed is a transport belt wherein an air-permeable transport belt comprising a mesh belt is formed from yarn comprising fiber strands of twisted yarn in a vertical direction extending in the transport direction, and cross yarn extending in such fashion as to cross the transport direction and intersecting the yarn comprising fiber strands in the vertical direction, the gap between warp yarns in the vertical direction being larger than the gap between cross yarns in the horizontal direction.
Tenth, proposed is a belt which is a mesh formed from cloth made in plain weave wherein the mesh pitch is set so as to be between 100 μm and 170 μm, the yarns from which the textile is made employ more solid yarn than twisted, i.e., twined, yarn, and the difference in height between warp yarns (vertical strands) and weft yarns (horizontal strands) where fibers intersect is set so as to be 20 μm to 100 μm.
However, the foregoing proposed conveyor belts which comprise mesh belts have the problem of fraying at the belt side ends. One way to address this fraying problem is to implement reinforcement processing at the belt side ends.
To improve strength and endurance, a mesh belt may be employed in which warp yarns are made thicker than weft yarns, diameter of warp yarns being made 1 mm to 2 mm, with diameter of weft yarns being made 0.1 mm to 0.5 mm.
To prevent meandering due to lateral displacement of the conveyor belt, a guide rib member for preventing lateral displacement may be arranged at the side ends of the mesh belt to carry out prevention of lateral displacement.
But because a mesh constituted from plain weave may require strategies including those for reinforcing strength and preventing lateral displacement and fraying at the side ends of the conveyor belt, e.g., strategies involving reinforcing materials and secondary treatment are required to prevent fraying, this can result in increased cost.
Moreover, if thickness of the warp yarn in the mesh is increased to 1 mm to 2 mm, this may cause it to be of insufficient flexibility for use as a conveyor belt.
As described above, with a conveyor belt having mesh construction which comprises woven fabric made in plain weave, to prevent lateral displacement due to meandering during conveying by the belt and to prevent fraying occurring at the belt side ends due to the fact that the entirety is of mesh construction, and because there are no steps at the belt surface, there has been the problem of secondary processing carried out to provide the belt side ends with guide members; and in addition, because strength is insufficient when the entire surface of the conveyor belt is in the form of a mesh belt, there has been the problem that extremely thick yarn was used to form the mesh belt so as to increase the strength thereof. Furthermore, where rubber is used as material for a conveyor belt in the form of a mesh belt, there has been the problem that machining was necessary to cause the belt to be provided with holes so that the belt comprising rubber could be made to have air permeability, which has caused increase in cost.
Problems to be solved by the present invention include elimination of problems such as the foregoing fraying of yarn at the side ends of the conveyor belt, meandering due to lateral displacement of the belt, need to install guide members at belt side ends, need to form the belt with thick yarn to compensate for lack of strength possessed by a mesh belt, increase in cost due to use of rubber material, and so forth, by providing a conveyor belt having mesh construction comprising woven fabric for permitting suction of air from below the belt and causing an object to be conveyed which is placed thereon to be conveyed at high speed, as well as a conveyor apparatus employing such a conveyor belt.